Estimating modifiable coronary heart disease risk in multiple regions of the world

: the INTERHEART Modifiable Risk Score

1. Catherine McGorrian1,2, 
2. Salim Yusuf1, 
3. Shofiqul Islam1, 
4. Hyejung Jung1,
5. Sumathy Rangarajan1, 
6. Alvaro Avezum3, 
7. Dorairaj Prabhakaran4,
8. Wael Almahmeed5, 
9. Zvonko Rumboldt6, 
10. Andrzej Budaj7, 
11. Antonio L. Dans8,
12. Hertzel C. Gerstein1, 
13. Koon Teo1 and 
14. Sonia S. Anand1,* on behalf of the INTERHEART Investigators
 

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Abstract

Aims Summating risk factor burden is a useful approach in the assessment of cardiovascular risk among apparently healthy individuals. We aimed to derive and validate a new score for myocardial infarction (MI) risk using modifiable risk factors, derived from the INTERHEART case–control study (n = 19 470).

Methods and results Multiple logistic regression was used to create the INTERHEART Modifiable Risk Score (IHMRS). Internal validation was performed using split-sample methods. External validation was performed in an international prospective cohort study. A risk model including apolipoproteins, smoking, second-hand smoke exposure, hypertension, and diabetes was developed. Addition of further modifiable risk factors did not improve score discrimination in an external cohort. Split-sample validation studies showed an area under the receiver-operating characteristic (ROC) curve c-statistic of 0.71 [95% confidence interval (CI): 0.70, 0.72]. The IHMRS was positively associated with incident MI in a large cohort of people at low risk for cardiovascular disease [12% increase in MI risk (95% CI: 8, 16%) with a 1-point increase in score] and showed appropriate discrimination in this cohort (ROC c-statistic 0.69, 95% CI: 0.64, 0.74). Results were consistent across ethnic groups and geographic regions. A non-laboratory-based score is also supplied.

Conclusions Using multiple modifiable risk factors from the INTERHEART case–control study, we have developed and validated a simple score for MI risk which is applicable to an international population.